Every Empire in history has always had some more equal than others, even if they aren’t quite the same as those at the very top. There were some very well off Indians indeed under the British Raj, and Brits and Indians below them...the ones at the top care about how far up the ladder they are as individuals, not whole groups. A Terran Empire is one with Earth ruling and at its centre, not one made up of just the human species, and in terms of maintaining order, it doesn’t work if you literally enslave everyone else. See also the Klingon-Cardassian Alliance and intendant Kira.
Egypt, Rome, heck, probably right back to city states like Ur, it never works if you subjugate everyone utterly. Rome had soldiers from the same races it enslaved, and vassal states are vassal states...often with an imperative to somehow ‘uplift’ what is seen as ‘savages’ like with Constantine evangelising to Anglo Saxon Britain even while having a few knocking about as slaves. As we also see in the MU, eventually the oppressed become the opressors unless another way is found.
Egypt, Rome, heck, probably right back to city states like Ur, it never works if you subjugate everyone utterly. Rome had soldiers from the same races it enslaved, and vassal states are vassal states...often with an imperative to somehow ‘uplift’ what is seen as ‘savages’ like with Constantine evangelising to Anglo Saxon Britain even while having a few knocking about as slaves. As we also see in the MU, eventually the oppressed become the opressors unless another way is found.
